1. Field of the Invention
The present invention relates to an apparatus and a method for selecting processing procedures executable in parallel (hereinafter referred to as "job steps") by a computer. Whether the job steps are eligible to be executed in parallel is determined by inspecting a relationship between a data set and a processing procedure for processing procedure groups generated without consideration of whether the processing procedure group can be placed into a series of parallel processing procedure groups (a series of processing procedures are referred to as "a plurality of job steps of JCL" in the present invention). In determining whether a processing procedure group can be placed into a series of parallel processing procedure groups, data set(s) corresponding to each processing procedure group are inspected to determine whether the data set is an exclusively used data set and whether the data set is a pipelined (pipe) data set. Job steps eligible to be executed in parallel are referred to as parallel-executable job steps.
2. Description of the Related Art
Job steps described by JCL (Job Control Language) are instructions of procedures. The job steps are conventionally based on a premise that the job steps are respectively executed in the sequence in which the job steps are written. In a computer comprising a plurality of instruction executing and processing sections, system efficiency can be improved through parallel execution of the job steps if the job steps of each job are normal. Particularly when subsequent job steps input and process the data of a data set output from the preceding job steps, the data set is implemented as a pipe data set by reserving a virtual file in a system storage without directly utilizing an access storage device or a magnetic tape apparatus. A pipe data set is a transient data set transferred from one job step to another. Consequently, generating JCL for accurately executing in parallel the parallel-executable job steps from the relationship between the same pipe data sets designated by a plurality of job steps and between exclusively used data sets has been difficult.